Patent GB-156254-A (GB)
Title: Manufacture of new tanning materials and process of tanning therewith
IPC: C14C3/04
Filed: 1921-01-04
Abstract: Synthetic tanning-agents obtained by coupling together organic compounds, such as heavy coal tar oil, tar phenols, phenol, creosote oil &c., by means of formaldehyde and sulphonation, are converted into aluminium or chromium salts, which also are tanning-agents, by treating the free acids or their salts, or mixtures thereof, with compounds containing aluminium or basic chromium or mixtures thereof. According to examples:-heavy coal-tar oil is sulphonated and condensed with formaldehyde, the free sulphuric acid is neutralized by potash, and the product is neutralized by aluminium hydroxide; tar phenols of boiling-point 185-200 DEG  C. are heated with sodium sulphite and formaldehyde solution, the product is acidified by sulphuric acid and the sulphur dioxide boiled off, and the product finally neutralized by chromium hydroxide; a mixture of naphthalene and phenol is sulphonated and condensed with formaldehyde, the product is diluted, neutralized with lime till only feebly acid, filtered, and finally neutralized with basic chromic sulphate; creosote oil is sulphonated and condensed with formaldehyde, and the product mixed with chromium sulphate and caustic soda solution until only feebly acid; a mixture of naphthalene and phenol is sulphonated and condensed with formaldehyde, the product is further condensed with tannin and formaldehyde, and finally neutralized by potash and aluminium hydroxide; a mixture of 2 : 6-naphthol sulphonic acid and glucose is condensed with formaldehyde and the product neutralized by chromium hydroxide.  The products may be used in tanning, alone or mixed with other tanning-agents, by any of the usual processes.ALSO:Synthetic tanning-agents obtained by coupling together organic compounds, such as heavy coal tar oil, tar phenols, phenols, creosote oil &c., by means of formaldehyde and sulphonation, are converted into aluminium or chromium salts, which also are tanning-agents, by treating the free acids or their salts, or mixtures thereof, with compounds of aluminium or basic chromium, or mixtures thereof.  According to examples:-heavy coal-tar oil is sulphonated and condensed with formaldehyde, the free sulphuric acid is neutralized by potash, and the product is neutralized by aluminium hydroxide; tar phenols of boiling-point 185-200 DEG  C. are heated with sodium sulphite and formaldehyde solution, the product is acidified by sulphuric acid and the sulphur dioxide boiled off, and the product finally neutralized by chromium hydroxide; a mixture of naphthalene and phenol is sulphonated and condensed with formaldehyde, the product is diluted, neutralized with lime till only feebly acid, filtered, and finally neutralized with basic chromic sulphate; creosote oil is sulphonated and condensed with formaldehyde, and the product mixed with chromium sulphate and caustic soda solution until only feebly acid; a mixture of naphthalene and phenol is sulphonated and condensed with formaldehyde, the product is further condensed with tannin and formaldehyde, and finally neutralized by potash and aluminium hydroxide; a mixture of 2 : 6-naphthol sulphonic acid and glucose is condensed with formaldehyde and the product neutralized by chromium hydroxide.  The products may be used in tanning, alone or mixed with other tanning-agents, by any of the usual processes.